Cell phone jammer I believe that we are not unfamiliar, in recent years, on the market a variety of shielding emerge in endlessly, everyone external claimed that their shielding is particularly good, the data is full of moisture, let you not clear the good and bad, so we should have a shield what kind of understanding?
The first point is that the higher the power of the mobile phone signal shielding device, the more remote the shielding effect will be. In fact, this is not completely correct. Many manufacturers deliberately exaggerate the openness of the shielding power by using ordinary users, which results in the loss of the reference value of the device’s nominal power index. For large shielding system, shielding technology is a decisive factor affecting shielding effect. The advantages of advanced shielding technology are far greater than the output power factor of shielding equipment.
The second is the use of directional antennas to avoid external interference. This is also incorrect because the directional antenna covers the main lobe, secondary lobe and rear lobe. The main lobe cover Angle is defined as the Angle included in the mobile phone signal shielding when the external power of the main lobe decreases by 3dB. In other words, the radiation intensity on the side and back of the directional antenna is only much lower than that of the main lobe. Therefore, if the space close to the antenna is still relatively shielded, the reflection of the shielded building will still cause external interference. In addition, if not properly used, will cause upstream interference, interference range will be larger. Therefore, whether the equipment technology can meet the conditions, the application of antenna, system debugging is far more significant than whether to use directional antenna.
The third point is that we all think the distance of the cell phone signal shielding is a hard indicator. Actually, distance is not absolute value. It is related to the strength and quality of the spatial signal. In short, distance is meaningless. For the same shielding power, if the distance is 100-70 decibels in the weak place, then only 12.5m in the strong -52 decibels. The shielding distance is related to the antenna gain. The same power shielding host USES different gain antennas, the distance will also be very different. For example, an antenna with a gain of 16 db is 100 meters away, and an antenna with a gain of 4DB is only 25 meters away.